Balancer

ABSTRACT

A balancer for balancing lawn mower blades having a frustroconical blade receiver on which the opening in a blade is placed, magnetic means surrounding the receiver for holding the blade on the receiver. An adjustable tracking device mounted on the base of the balancer with the tip disposable adjacent the position of a blade mounted on the balancer.

United States Patent Karrels [451 May 2,1972

[ BALANCER [72] Inventor: Alvin J. Karrels, Route 1, Port Washington, Wis. 53074 [22] Filed: Dec. 26, 1967 [21] Appl. No.: 693,564

[52] US. Cl ..73/480 [51] Int. Cl. ..G0lm 1/12 [58] Field of Search ..73/480, 482, 455, 456; 33/169, 33/203.16, 203.19

[56] References Cited UNITED STATES PATENTS 1,410,224 3/1922 Schwartz 33/203 19 1,903,051 3/1933 Kennedy 33/203. 19 1,977,297 10/1934 Weaver.... 33/203.16 2,075,421 3/1937 Bennett 33/203. 16 2,177,921 10/1939 Zofrey 74/2428 2,524,407 10/1950 Trindle ..73/482 2,531,799 1 1/1950 Zumwalt ..73/480 2,718,781 9/1955 Kiebert ..73/484 2,992,489 7/1961 Karrels ..33/169 2,987,924 6/1961 Karrels ..73/480 3,177,725 4/1965 Johnson ..73/480 FOREIGN PATENTS OR APPLICATIONS 750,987 6/1956 Great Britain ..73/483 528,177 10/1950 Great Britain ..73/480 Primary Examiner-James J. Gill Assistant Examiner-H. Goldstein Anorney-l-liram A. Sturges ABSTRACT A balancer for balancing lawn mower blades having a frustroconical blade receiver on which the opening in a blade is placed, magnetic means surrounding the receiver for holding the blade on the receiver.

An adjustable tracking device mounted on the base of the balancer with the tip disposable adjacent the position of a blade mounted on the balancer.

1 Claims, 4 Drawing Figures PATENTEDMAY 2 I972 3, 659,463

SHEET 2 OF 2 ALVIN J. KARRELS BALANCER In the prior art, the balancer most similar to the balancer of this invention is in the U.S. Pat. No. 2,987,924, issued June 13, 1961, to myself, and titled, BLADE BALANCER. In the earlier patent, a work-piece such as a lawn mower blade, was placed with its opening on a cone. Next, a sliding magnet mounted on the axle of the balancer was allowed to slide up to the blade and magnetically grip it to hold it in place on the cone. The sizes of work-piece openings which could be received on the earlier balancer was limited, however, because its cone could not be removed conveniently for replacement with a cone of greater size.

It is, therefore, a object of this invention to provide a balancer with a readily replaceable work-piece engaging member.

In the earlier patent mentioned, an adjustable track checker is shown. However, it is an object of this invention to provide a more versatile track checker in which a carrier shaft is mounted on the base of the balancer in a manner giving it both lengthwise and rotational adjustability similarly to the adjustability afforded by the checking arm itself in the earlier patent. However, it is an object of this invention to provide a checking arm mounted on such a carrier shaft in a manner afi'ording the checking arm an adjustability along the carrier shaft, rotationally of the carrier shaft, and lengthwise of itself and a means attaching the arm to the carrier shaft, and also rotational adjustment with respect to the attaching means. The checking assembly itself is adapted to telescope.

FIG. 1 is a frontal elevation of the blade balancer of this invention.

FIG. 2 is a side elevation of the balancer of FIG. 1.

FIG. 3 is a sectional view of the balancer taken along the line 3--3 of FIG. 1.

FIG. 4 is a sectional view of the track checker taken along the line 4-4 of FIG. 1, two shafts being shown in section.

The balancer of this invention is generally indicated at in FIG. 1 and comprises a base 12, a normally horizontal shaft 20, best seen in FIG. 3, a hub 30 fixed on the shaft by set screw 32 for rotation therewith.

Means are provided for holding the hub 30 at a spacing from the base comprising a collar 34 disposed between hub 30 and a outer bearing 40 held in place by a snap ring 42 in the base 12.

On the inner side of the outer bearing 40 is an annular holder 48 with set screw 50 engaging the shaft 20 and preventing the bearing 40 from moving inwardly of the hub. A spacing sleeve 54 extends from the holder 48 to an inner bearing 58 held in place by snap ring 60 in the hub 12, which latter is on that side of the bearing 58 which is opposite the bearing 40. A snap-in disc 70 covers an opening 72 in the hub 12 in which the bearings 40 and 58 are received.

A magnetic means is generally indicated at 100 having a magnetic work-engaging surface 102 arranged approximately in a circle with its center on the axis 110 about which the axle 20 rotates.

The work-engaging surface 102 is formed of an outermost ring 106 of material-carrying magnetism, and an innermost ring 108 likewise of material-carrying magnetism, these rings being separated by a non-magnetic bonding cement 112, which latter is annularly disposed between magnetic members 120 and 122 disposed on the inner side and the outer side respectively of a magnetic disc 126 which is annular and which surrounds the non-magnetic hub 30.

A work-receiving member 200 is provided having a workreceiving outer surface 202 of an annular shape and inclined with respect to the axis 110 and a circular exterior in any cross-section taken normally of the axis, and of greater diameter on that side thereof which is nearest the base 12, with its opposite side accessible to a work-piece 220 shown in dotted lines in FIG. 2, and having a circular opening therethrough of a size for reception of its wall against the surface 202.

The work-engaging member 200 is slidably received in the shaft 20 and is urged away from the magnetic surface 102 by a spring 230 which engages the hub 30. The spring can be any kind of resilient means and the work-receiving member 200 is held on the shaft 20 by a removable bolt 240, whereby the work-engaging member 200 can be replaced with a smaller one or a larger one for balancing difierent kinds of work.

A track checker is generally indicated at 270 and has an elongated carrier shaft 272 received in the holder 274 secured to a post 276 on the base by a bolt 278, the latter making the holder 274 and shaft 272 pivotally mounted on the post for swinging in the direction of the arrow 280.

A second shaft 290 is provided received against the concave surface of a first U-shaped member 294.

The second substantially U-shaped member 296 receives the first shaft 272 against its concave surface and extending arm portions 299 of the U-shaped members 294, 296 are disposed in parallelism and lapping relationship, whereby a tightening means comprising a bolt 300 extending through the arm portions and having a nut 302 thereon engaging a spring 304, can draw the arm portions toward each other, clamping the shafts 272 and 290 respectively in their U-shaped members, whereby upon a loosening of the tightening means or bolt 300, the U-shaped members can be rotated around the bolt 300, or either shaft can be moved lengthwise with respect to the U-shaped members 294 or 296.

The shaft 290 is hollow and at its outer end are members 310 which together with the shaft 290 form a telescoping assembly having a transverse portion 320 at its outermost end having sighting ball 324 on its tip which, with all the various adjustments, can be placed in any suitable position for determining whether difierent portions of the work-piece 220 passing the ball 324 are at a properly equal distance therefrom, or whether they need correction.

As thus described, the balancer of this invention is believed to fulfill the objectives above set forth providing a more versatile balancer for balancing work-pieces of more varying sizes and shapes and with openings of more varying size.

I claim:

1. A balancer comprising: a base, a normally horizontal shaft having a rotational axis, a hub on said shaft, means holding said hub at a spacing from said base, magnetic means presenting magnetized work-engaging surface means arranged annularly around said axis, said work-engaging surface being disposed substantially in a plane extending normally with respect to said axis, means attaching said magnetic means on said hub, a work-receiving member having a work-receiving outer surface of an inclined annular shape and of circular ex terior in any cross-section taken normally of said axis, said work-receiving surface being disposed on the exterior of said balancer and having an annular portion of greater diameter disposed on the side thereof which is closest to said base, the opposite side of said work-receiving surface being accessible to a work-piece having a circular opening therethrough of a size for reception of its wall against said work-receiving surface, said work-receiving member being slidably received on said shaft for movement longitudinally of said shaft with a slidable fit sufl'iciently snug as to maintain portions of said work-receiving surface which are disposed at equal distances from said axis in substantially a same plane normal to said axis, means attached to said shaft and engaging said work-receiving member for preventing said work-receiving member from moving off of said shaft in a direction away from said hub, and resilient means engaging said work-receiving member and also engaging a part of said balancer disposed on the base side of said work-receiving member and urging said work-receiving member along said axis in a direction away from said hub whereby when a work-piece as described is disposed with its said opening receiving said work-receiving outer inclined surface, said magnetic means will attract said work-piece and will hold it against said magnetic work-engaging annular surface while said urging means will force said inclined annular surface in a direction away from said hub and firmly to the said opening of said work-piece for holding said work-piece with the center of its opening on said axis, said balancer further having a track checker comprising: an elongated carrier shaft,

means mounting said carrier shaft on said base in an adjustable manner whereby said carrier shaft can be moved longitudinally and can be clamped in various longitudinal positions with respect to said base, said mounting means attaching said carrier shaft to said base pivotally for pivoting about a pivot axis for permitting a tilting of said carrier shaft about said pivot axis for the positioning of the ends of said carrier shaft various distances from said base respectively, a second shaft, means attaching said shafts together comprising a U-shaped member having said carrier shaft against its concave surface, a second substantially U-shaped member receiving said second shaft against its concave surface, each of said U-shaped members having extended arm portions disposed approximately in parallelism, and a tightening means comprising a bolt extending through said arm portions and adapted to hold said arm portions together and to draw respective arm portions toward each other for clamping said shafts respectively in their U- shaped members whereby upon a loosening of said tightening means said U-shaped members can be rotated around said bolt, or saidclamping U-shaped members can be adjusted along the length of or rotated around either of said shafts, said frustro-conical blade receiver being disposed generally in a plane, said shafts being elongated in a vertical direction, a transverse shaft attached to the outer end of said second shaft and elongated in a horizontal direction extending out to a position adjacent the plane of said frustro-conical blade receiver.

1" i i i 

1. A balancer comprising: a base, a normally horizontal shaft having a rotational axis, a hub on said shaft, means holding said hub at a spacing from said base, magnetic means presenting magnetized work-engaging surface means arranged annularly around said axis, said work-engaging surface being disposed substantially in a plane extending normally with respect to said axis, means attaching said magnetic means on said hub, a workreceiving member having a work-receiving outer surface of an inclined annular shape and of circular exterior in any crosssection taken normally of said axis, said work-receiving surface being disposed on the exterior of said balancer and having an annular portion of greater diameter disposed on the side thereoF which is closest to said base, the opposite side of said workreceiving surface being accessible to a work-piece having a circular opening therethrough of a size for reception of its wall against said work-receiving surface, said work-receiving member being slidably received on said shaft for movement longitudinally of said shaft with a slidable fit sufficiently snug as to maintain portions of said work-receiving surface which are disposed at equal distances from said axis in substantially a same plane normal to said axis, means attached to said shaft and engaging said work-receiving member for preventing said workreceiving member from moving off of said shaft in a direction away from said hub, and resilient means engaging said workreceiving member and also engaging a part of said balancer disposed on the base side of said work-receiving member and urging said work-receiving member along said axis in a direction away from said hub whereby when a work-piece as described is disposed with its said opening receiving said work-receiving outer inclined surface, said magnetic means will attract said work-piece and will hold it against said magnetic work-engaging annular surface while said urging means will force said inclined annular surface in a direction away from said hub and firmly to the said opening of said work-piece for holding said work-piece with the center of its opening on said axis, said balancer further having a track checker comprising: an elongated carrier shaft, means mounting said carrier shaft on said base in an adjustable manner whereby said carrier shaft can be moved longitudinally and can be clamped in various longitudinal positions with respect to said base, said mounting means attaching said carrier shaft to said base pivotally for pivoting about a pivot axis for permitting a tilting of said carrier shaft about said pivot axis for the positioning of the ends of said carrier shaft various distances from said base respectively, a second shaft, means attaching said shafts together comprising a U-shaped member having said carrier shaft against its concave surface, a second substantially U-shaped member receiving said second shaft against its concave surface, each of said U-shaped members having extended arm portions disposed approximately in parallelism, and a tightening means comprising a bolt extending through said arm portions and adapted to hold said arm portions together and to draw respective arm portions toward each other for clamping said shafts respectively in their U-shaped members whereby upon a loosening of said tightening means said U-shaped members can be rotated around said bolt, or said clamping Ushaped members can be adjusted along the length of or rotated around either of said shafts, said frustro-conical blade receiver being disposed generally in a plane, said shafts being elongated in a vertical direction, a transverse shaft attached to the outer end of said second shaft and elongated in a horizontal direction extending out to a position adjacent the plane of said frustroconical blade receiver. 